Laserfiche WebLink
<br /> <br />339 free drainage. In case the aggregates contain high or non-uniform moisture content, <br />340 storage or stockpile period in excess of 12 hours may be required. <br />341 <br />342 (d) Bins and Scales. The batching plant may include bins, weighing hoppers, and scales for <br />343 the fine aggregate and for each size of coazse aggregate. If cement its used in bulk, a bin, <br />344 hopper, and scale for cement shall be included. A single weighing hopper with an ' <br />345 accumulative scale will be permitted, provided a separate scale its used for weighing <br />346 <br />347 cement. <br />348 Scales shall meet the requirements of subsection 109.01. <br />349 <br />350 <br />601.07 Mixing. Concrete may be mixed in stationary mixers, in a central-mix plant, in truck ' <br />351 mixers, or in self-contained mobile mixers. Mixing time shall be measuc•ed from the time all <br />352 materials, except water, are in the dnrm. Silica fume, when specified, shall be added to the mix <br />353 during initial batching. <br />354 <br />355 (a) Mixing General. The concrete shall be deposited in place within 90 minutes after batching <br />356 when concrete is delivered in truck mixers or agitating trucks, and within 60 minutes when <br />357 delivered in non agitating trucks. <br />358 <br />359 The 90 minute time limit for mixer or agitating trucks may be extended to 120 minutes if: <br />360 <br />361 (1) No water is added afer 90 minutes. <br />362 <br />363 (2) The concrete temperature prior to placement is less than 90 °F The: 90 minute time limit <br />364 for mixer or agitating trucks may be extended to 180 minutes if: <br />t <br />365 . <br />366 (1) No water is added after 90 minutes. <br />367 <br />368 (2) The concrete temperature prior to placement is less than 90 °F. <br />369 <br />370 (3) The approved concrete mix contains a water reducing and retarding admixture which <br />371 conforms to AASHTO M 194, Type D. <br />372 <br />373 (b) Stationary Mixing. When mixed in a central mixing plant, the mixing time shall be between <br />374 50 and 90 seconds. Four seconds shall be added to the specified mixing time if timing starts <br />375 the instant the skip reaches its maximum raised position. Mixing time ends when the <br />376 dischazge chute opens. Transfer time in multiple drum mixers is included in mixing time. The <br />377 contents of an individual mixer drum shall be removed before a succeeding batch is emptied <br />378 therein. <br />379 <br />380 The volume of concrete mixed per batch may exceed the mixer's nominal capacity, as shown <br />381 on the manufacturer's standazd rating plate on the mixer, up to 10 per cent provided concrete <br />382 test data for strength, segregation, and uniform consistency are satisfactory, and provided <br />383 spillage of concrete does not occur. <br /> , <br /> 3-38 <br /> G.\101\00100 OTq\Repo~sV(P\Teginiral Spacificatima Eoc FeEruary 3. 20°6 <br /> <br />